First author Puhua Wan (IMAGE) University of Groningen Caption First author Puhua Wan produced the samples that fulfilled all the requirements to show that there is indeed a finite momentum in the Cooper pairs. | Photo P. Wan / University of Groningen Credit P. Wan / University of Groningen Usage Restrictions Credit must be given to the creator. Adaptations must be shared under the same terms. License CC BY-SA Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.